I have read that unlike boar hair brushes, badger brushes don't have a break-in period. But I have noticed that my Frank silvertip has definitely improved over time. I face lather, and at first it didn't lather well at all; now it produces great lather very quickly. I just noticed the difference recently. So is it now brocken in?

Ilnones, my perception is that after a half dozen or so uses, most badger brushes are 95-99% capable of being all they can be. I did find that denser brushes such as Chubby 2s and 3s were more along the lines of a dozen or more (15-18, maybe?) shaves before they got to that point. As they say though, ymmv.

Badger brushes don't break in like boar brushes do. However, badger knots will open and loosen after some use. This results in the knot performing and feeling better, and can be seen as a type of breaking in. How long this takes depends on the type of badger hair involved. For most badger brushes I think it just takes a few uses. Some of the firmer badger hair, like Simpson Manchurian or Shavemac D01 2-band, or very dense brushes, like the Chubby, will take longer.

Can state with certainty with Kent brushes of differing badger hair and density that there is absolutely deltas in breakin required. The lower grade of hair or denser the knot, longer the breakin period and/or treatments required to get to the final state. Presumably applies in a catholic manner but insufficient experience across other various brands and hair grades/density to state with certainty.

I can't say I'm a huge fan of badger brushes in general, I prefer my synthetics. I have a Semogue OC 2Band bought on 2012( from the previous stiffer batch), which took some time to break in, about 10-15 shaves.